Stacked silicon devices may include multiple dies connected through an interposer, which is then mounted on a package substrate. This allows for increased functionality of a stacked silicon device, as several different dies performing different functions may be packaged together in a single stacked silicon device.
Conventionally, during formation of the stacked silicon device, the multiple dies are exposed during several of the process steps. It is hypothesized that during some of the process steps, including mold encapsulation/grinding and bonding/removing of a carrier wafer, the dies may be exposed to charge. Such exposure to charge leads to potential damage of the dies and consequently undesired behavior of the dies. One particular type of undesired behavior exhibited by dies that are exposed to charge during formation of the stacked silicon device is a poor readback yield. If the dies have memory cells, the memory cells of the dies may become damaged during formation of the stacked silicon device such that incorrect/incomplete data is subsequently read back from memory cells.
Because such charge exposure of dies during formation of stacked silicon devices may potentially lead to undesired behavior, it may be desirable to protect the dies from potential exposure to charge during packing of the stacked silicon device.